Holocene climate and landscape evolution East of the Pechora Delta, East-European Russian Arctic

Abstract

This study presents a multiproxy record of Holocene environmental change in the region East of the Pechora Delta. A peat plateau profile (Ortino II) is analyzed for plant macrofossils, sediment type, loss on ignition, and radiocarbon dating. A paleosol profile (Ortino III) is described and radiocarbon dated. A previously published peat plateau profile (Ortino I) was analyzed for pollen and conifer stomata, loss on ignition, and radiocarbon dating. The interpretation of the latter site is reassessed in view of new evidence. Spruce immigrated to the study area at about 8900 14C yr B.P. Peatland development started at approximately the same time. During the Early Holocene Hypsithermal taiga forests occupied most of the present East-European tundra and peatlands were permafrost free. Cooling started after 5000 14C yr B.P., resulting in a retreat of forests and permafrost aggradation. Remaining forests disappeared from the study area around 3000 14C yr B.P., coinciding with more permafrost aggradation. The retreat of forests resulted in landscape instability and the redistribution of sand by eolian activity. The displacement of the Arctic forest line and permafrost zones indicates a warming of at least 2–3°C in mean July and annual temperatures during the Early Holocene. At least two cooling periods can be recognized for the second half of the Holocene, starting at about 4800 and 3000 14C yr B.P.

Holocene Development and Permafrost History of the Usinsk Mire, Northeast European Russia

“…This peat plateau is located in the modern forest-tundra zone, about 280 km to the northeast of the Usinsk mire. Also, the Ortino I peat plateau (Väliranta et al, 2003) probably formed around this time. Conditions at the site of profile USI 1 in Usinsk remained permafrost-free through these time intervals, although an unstable embryonic palsa might have developed briefly around ca.…”

“…4800 BP (Väliranta et al, 2003). It is reported from the Ortino II peat plateau in the modern tundra zone, located about 280 km to the northwest of the Usinsk study area.…”

“…Plant macrofossil studies with radiocarbon dates from mires are reported in Oksanen et al (1998Oksanen et al ( , 2001) from the foresttundra zone and in Väliranta et al (2003) from the tundra zone. The same methods used in these previous studies are applied to the Usinsk mire, in the northern taiga, in order to compare the age and dynamics of permafrost in different eco-climatic zones.…”

A Richer, Greener and Smaller Alpine World: Review and Projection of Warming-Induced Plant Cover Change in the Swedish Scandes

“…In fact, such a course of landscape evolution adds to physical and ecological stability, functional efficiency, resilience and assures against 'system failure' (McCann 2000;Körner 2002;McLaren 2006). Also paleoecological inferences support the notion of a positive relationship between ambient temperature rise, plant-cover progression and landscape stability (Väliranta et al 2003). Moreover, the accretion of certain exotic species to the rising vascular plant richness may generate high-mountain plant communities better adapted to unknown future climates (Bradshaw 1995).…”

Lake stratigraphy implies an 80 000 yr delayed melting of buried dead ice in northern Russia

“…The tree trunks show that the area was forested, corresponding with the period between 9000 and 4000 14 C yr BP when the northern treeline reached the Barents Sea coast (Khotinskiy, 1984;Kremenetski et al, 1998;MacDonald et al, 2000). We find it probable that the formation of the ice-wedges, which post-date the peat, started at the same time as the deforestation around 4 ka, during the late Holocene, cooling with subsequent southward shift in permafrost distribution (Baulin et al, 1984;Väliranta et al, 2003).…”